Vitamin D-dependent calcium-binding protein

Vitamin D-dependent calcium binding proteins were discovered in the cytosolic fractions of chicken intestine, and later in mammalian intestine and kidney, by workers including Robert Wasserman of Cornell University.[1][2]

They bound calcium in the micromolar range and were greatly reduced in vitamin D-deficient animals. Expression could be induced by treating these animals with vitamin D metabolites such as calcitriol.

They were found to exist in two distinct sizes with a molecular weight of approximately 9 kDa and 28 kDa. They were renamed calbindin. Calbindin-D9k (S100G) is found in mammalian intestine and calbindin-D28k is in avian intestine and in mammalian kidney and other tissues.